ONE FORMULA, ONE ANSWER
Rocket Nozzle Thrust Calculator
Calculate axial rocket nozzle thrust from exhaust momentum and the exit-to-ambient pressure difference. Choose input units and calculate one value within the stated conditions.
Inputs
Calculations run in this browser. Scientific notation such as 1.2e-3 is supported. Do not group thousands.
Result
Axial thrust F
Enter values and select Calculate.
F = ṁv_e + (p_e−p_a)A_e
Assumptions
Required: ṁ,A_e>0, 0<v_e<c and nonnegative absolute pressures. Quasi-steady axial exhaust with uniform exit velocity and pressure is assumed, without external air ingestion. Excluded: internal nozzle solutions, efficiency, back-pressure separation and unsteady flow. The pressure contribution may be negative; the output is signed along the chosen thrust axis.
Displayed values are floating-point approximations. Design safety factors and unprovided error contributions are not calculated.
Formula references and credits
NaNa Lab created the code, descriptions, icons and preview images. Text, figures and code from the linked references have not been reproduced.
Physical constants: NIST / CODATA 2022. The values of μ₀ and ε₀ are measured recommendations, not exact defining constants. Values and precision notes are in the source record.
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